The relationship between tissue factor and cancer progression: insights from bench and bedside. Blood. 2012;119:924-932. [PMID: 22065595 DOI: 10.1182/blood-2011-06-317685]

A novel scoring system based on hemostatic parameters predicts the prognosis of patients with advanced pancreatic cancer

OBJECTIVE

The aim of this study was to evaluate the prognostic value of pre-treatment plasma hemostatic parameters in patients with advanced pancreatic cancer.

METHODS

A total of 320 patients diagnosed with advanced pancreatic cancer between January 1, 2011 to December 31, 2015 were enrolled in this retrospective study. The prognostic significance of hemostatic parameters such as prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FBG), platelet count (PLT), mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) was determined by univariate and multivariate Cox hazard models. Then, Kaplan-Meier methods and log-rank tests were performed to compare the survival of patients in different risk groups.

RESULT

Univariate and multivariate analyses showed that prolonged PT, high FBG, and high MPV were independent prognostic factors for poor overall survival (PT > 11.3 s, HR = 1.46, 95%CI = 1.10-1.94, p = 0.009; FBG>2.5 g/L, HR = 1.41, 95%CI = 1.08-1.84, p = 0.011; MPV>12.2 fL, HR = 1.52, 95%CI = 1.13-2.04, p = 0.005). Moreover, all the patients were stratified into three groups by a scoring system based on these three hemostatic markers. The median survival time of the three groups was 8.8 months, 6.3 months and 4.3 months (P < 0.001).

CONCLUSION

PT, FBG and MPV were independent prognostic factors in advanced pancreatic cancer. A novel scoring system based on these hemostatic parameters could be used to predict the survival of patients with advanced pancreatic cancer.

D-dimer increase: an unfavorable factor for patients with primary liver cancer treated with TACE

PURPOSE

To explore the clinical significance of plasma D-dimer increase for transcatheter arterial chemoembolization (TACE) in patients with primary liver cancer (PLC).

METHODS

The clinical data of 80 PLC patients who underwent TACE in our hospital from January 2015 to January 2017 were collected, including the plasma D-dimer level 1 week before TACE (D0), D-dimer level 1 month after TACE (D1) and D-dimer level when the disease begins to progress (D2). 1 Month after TACE, these patients were divided into two groups according to the mRecist criteria: disease-controlled group (CR + PR + SD) and disease-progressing group (PD). In all subjects, progression-free survival (PFS) was recorded. D0 and D1 were compared between the two groups by the rank sum test; and the relation between D-dimer level and PFS was assessed by the Kaplan-Meier test and Breslow test.

RESULTS

In the disease-controlled group, there was no significant difference between D0 and D1 (P > 0.05); in the disease-progressing group, D1 was significantly higher than D0 (P < 0.05) and the D1 is higher than that in disease-controlled group. In the patients with a negative D1 or D2, PFS was longer than those with a positive level (both P < 0.05), but such difference was not statistically significant in D0 (P > 0.05). In the patients with a D-dimer level increase after TACE (group 3), PFS was shorter than that in those with a D-dimer level decrease after TACE (Group 1) and that in those with a relatively stable D-dimer level before and after TACE (Group 2) (P < 0.05); survival in Group 1 was slightly but not significantly longer than that in Group 2 (P > 0.05).

CONCLUSION

The change in plasma D-dimer level can be used as a biological index to assess the efficacy of TACE and prognosis for PLC patients, and thus, a positive D-dimer level or D-dimer increase after TACE is an unfavorable factor.

Tisotumab vedotin in patients with advanced or metastatic solid tumours (InnovaTV 201): a first-in-human, multicentre, phase 1-2 trial

BACKGROUND

Tisotumab vedotin is a first-in-human antibody-drug conjugate directed against tissue factor, which is expressed across multiple solid tumour types and is associated with poor clinical outcomes. We aimed to establish the safety, tolerability, pharmacokinetic profile, and antitumour activity of tisotumab vedotin in a mixed population of patients with locally advanced or metastatic (or both) solid tumours known to express tissue factor.

METHODS

InnovaTV 201 is a phase 1-2, open-label, dose-escalation and dose-expansion study done at 21 centres in the USA and Europe. Patients (aged ≥18 years) had relapsed, advanced, or metastatic cancer of the ovary, cervix, endometrium, bladder, prostate, oesophagus, squamous cell carcinoma of the head and neck or non-small-cell lung cancer; an Eastern Cooperative Oncology Group performance status of 0-1; and had relapsed after or were not eligible to receive the available standard of care. No specific tissue factor expression level was required for inclusion. In the dose-escalation phase, patients were treated with tisotumab vedotin between 0·3 and 2·2 mg/kg intravenously once every 3 weeks in a traditional 3 + 3 design. In the dose-expansion phase, patients were treated at the recommended phase 2 dose. The primary endpoint was the incidence of adverse events, including serious adverse events, infusion-related, treatment-related and those of grade 3 or worse, and study drug-related adverse events, analysed in all patients who received at least one dose of tisotumab vedotin (full analysis population). This trial is registered with ClinicalTrials.gov, number NCT02001623, and is closed to new participants with follow-up ongoing.

FINDINGS

Between Dec 9, 2013, and May 18, 2015, 27 eligible patients were enrolled to the dose-escalation phase. Dose-limiting toxicities, including grade 3 type 2 diabetes mellitus, mucositis, and neutropenic fever, were seen at the 2·2 mg/kg dose; therefore, 2·0 mg/kg of tisotumab vedotin intravenously once every 3 weeks was established as the recommended phase 2 dose. Between Oct 8, 2015, and April 26, 2018, 147 eligible patients were enrolled to the dose-expansion phase. The most common (in ≥20% of patients) treatment-emergent adverse events of any grade were epistaxis (102 [69%] of 147 patients), fatigue (82 [56%]), nausea (77 [52%]), alopecia (64 [44%]), conjunctivitis (63 [43%]), decreased appetite (53 [36%]), constipation (52 [35%]), diarrhoea (44 [30%]), vomiting (42 [29%]), peripheral neuropathy (33 [22%]), dry eye (32 [22%]), and abdominal pain (30 [20%]). The most common adverse events of grade 3 or worse were fatigue (14 [10%] of 147 patients), anaemia (eight [5%]), abdominal pain (six [4%]), hypokalaemia (six [4%]), conjunctivitis (five [3%]), hyponatraemia (five [3%]), and vomiting (five [3%]). 67 (46%) of 147 patients had a treatment-emergent serious adverse event. 39 (27%) of 147 patients had a treatment-emergent serious adverse event related to the study drug. Infusion-related reactions occurred in 17 (12%) of 147 patients. Across tumour types, the confirmed proportion of patients who achieved an objective response was 15·6% (95% CI 10·2-22·5; 23 of 147 patients). There were nine deaths across all study phases (three in the dose-escalation phase and six in the dose-expansion phase); only one case of pneumonia in the dose-expansion phase was considered possibly related to study treatment.

INTERPRETATIONS

Tisotumab vedotin has a manageable safety profile with encouraging preliminary antitumour activity across multiple tumour types in heavily pretreated patients. Continued evaluation of tisotumab vedotin is warranted in solid tumours.

FUNDING

Genmab A/S.

Oxime Coupling of Active Site Inhibited Factor Seven with a Nonvolatile, Water-Soluble Fluorine-18 Labeled Aldehyde

A nonvolatile fluorine-18 aldehyde prosthetic group was developed from [¹⁸F]SFB, and used for site-specific labeling of active site inhibited factor VII (FVIIai). FVIIai has a high affinity for tissue factor (TF), a transmembrane protein involved in angiogenesis, proliferation, cell migration, and survival of cancer cells. A hydroxylamine N-glycan modified FVIIai (FVIIai-ONH₂) was used for oxime coupling with the aldehyde [¹⁸F]2 under mild and optimized conditions in an isolated RCY of 4.7 ± 0.9%, and a synthesis time of 267 ± 5 min (from EOB). Retained binding and specificity of the resulting [¹⁸F]FVIIai to TF was shown in vitro. TF-expression imaging capability was evaluated by in vivo PET/CT imaging in a pancreatic human xenograft cancer mouse model. The conjugate showed exceptional stability in plasma (>95% at 4 h) and a binding fraction of 90%. In vivo PET/CT imaging showed a mean tumor uptake of 3.8 ± 0.2% ID/g at 4 h post-injection, a comparable uptake in liver and kidneys, and low uptake in normal tissues. In conclusion, FVIIai was labeled with fluorine-18 at the N-glycan chain without affecting TF binding. In vitro specificity and a good in vivo imaging contrast at 4 h postinjection was demonstrated.

Roles of Coagulation Proteases and PARs (Protease-Activated Receptors) in Mouse Models of Inflammatory Diseases

Activation of the blood coagulation cascade leads to fibrin deposition and platelet activation that are required for hemostasis. However, aberrant activation of coagulation can lead to thrombosis. Thrombi can cause tissue ischemia, and fibrin degradation products and activated platelets can enhance inflammation. In addition, coagulation proteases activate cells by cleavage of PARs (protease-activated receptors), including PAR1 and PAR2. Direct oral anticoagulants have recently been developed to specifically inhibit the coagulation proteases FXa (factor Xa) and thrombin. Administration of these inhibitors to wild-type mice can be used to determine the roles of FXa and thrombin in different inflammatory diseases. These results can be compared with the phenotypes of mice with deficiencies of either Par1 (F2r) or Par2 (F2rl1). However, inhibition of coagulation proteases will have effects beyond reducing PAR signaling, and a deficiency of PARs will abolish signaling from all proteases that activate these receptors. We will summarize studies that examine the roles of coagulation proteases, particularly FXa and thrombin, and PARs in different mouse models of inflammatory disease. Targeting FXa and thrombin or PARs may reduce inflammatory diseases in humans.

Near-infrared photoimmunotherapy of pancreatic cancer using an indocyanine green-labeled anti-tissue factor antibody

AIM

To investigate near-infrared photoimmunotherapeutic effect mediated by an anti-tissue factor (TF) antibody conjugated to indocyanine green (ICG) in a pancreatic cancer model.

METHODS

Near-infrared photoimmunotherapy (NIR-PIT) is a highly selective tumor treatment that utilizes an antibody-photosensitizer conjugate administration, followed by NIR light exposure. Anti-TF antibody 1849-ICG conjugate was synthesized by labeling of rat IgG_2b anti-TF monoclonal antibody 1849 (anti-TF 1849) to a NIR photosensitizer, ICG. The expression levels of TF in two human pancreatic cancer cell lines were examined by western blotting. Specific binding of the 1849-ICG to TF-expressing BxPC-3 cells was examined by fluorescence microscopy. NIR-PIT-induced cell death was determined by cell viability imaging assay. In vivo longitudinal fluorescence imaging was used to explore the accumulation of 1849-ICG conjugate in xenograft tumors. To examine the effect of NIR-PIT, tumor-bearing mice were separated into 5 groups: (1) 100 μg of 1849-ICG i.v. administration followed by NIR light exposure (50 J/cm²) on two consecutive days (Days 1 and 2); (2) NIR light exposure (50 J/cm²) only on two consecutive days (Days 1 and 2); (3) 100 μg of 1849-ICG i.v. administration; (4) 100 μg of unlabeled anti-TF 1849 i.v. administration; and (5) the untreated control. Semiweekly tumor volume measurements, accompanied with histological and immunohistochemical (IHC) analyses of tumors, were performed 3 d after the 2^nd irradiation with NIR light to monitor the effect of treatments.

RESULTS

High TF expression in BxPC-3 cells was observed via western blot analysis, concordant with the observed preferential binding with intracellular localization of 1849-ICG via fluorescence microscopy. NIR-PIT-induced cell death was observed by performing cell viability imaging assay. In contrast to the other test groups, tumor growth was significantly inhibited by NIR-PIT with a statistically significant difference in relative tumor volumes for 27 d after the treatment start date [2.83 ± 0.38 (NIR-PIT) vs 5.42 ± 1.61 (Untreated), vs 4.90 ± 0.87 (NIR), vs 4.28 ± 1.87 (1849-ICG), vs 4.35 ± 1.42 (anti-TF 1849), at Day 27, P < 0.05]. Tumors that received NIR-PIT showed evidence of necrotic cell death-associated features upon hematoxylin-eosin staining accompanied by a decrease in Ki-67-positive cells (a cell proliferation marker) by IHC examination.

CONCLUSION

The TF-targeted NIR-PIT with the 1849-ICG conjugate can potentially open a new platform for treatment of TF-expressing pancreatic cancer.

Single cell coagulomes as constituents of the oncogene-driven coagulant phenotype in brain tumours

Molecular profiling of human cancers revealed a startling diversity in disease-causing mechanisms superseding histological and anatomical commonalities. The emerging molecular subtypes and disease entities are often driven by distinct oncogenic pathways and their effectors, including those acting extracellularly on the vascular and coagulation systems. Indeed, several oncogenic mutations such as those affecting protein-coding genes (RAS, EGFR, PTEN, TP53) and non-coding RNA (microRNA) regulate multiple effectors of the coagulation system (coagulome), including tissue factor, protease activated receptors, clotting factors, mediators of platelet function and fibrinolysis. This is exemplified by differential coagulome profiles in the molecular subtypes of glioblastoma, medulloblastoma and other human tumours. There is mounting clinical evidence that the mutational status of cancer driver genes such as KRAS or IDH1 may influence the risk of venous thromboembolism in patients with colorectal, lung or brain cancers. Notably, single cell sequencing in glioblastoma revealed a remarkable intra-tumoural heterogeneity of cancer cell populations with regard to their individual coagulomes, suggesting a combinatorial and dynamic nature of the global pro-thrombotic phenotype. We suggest that the cellular complexity of specific cancers may define their mechanisms of interactions with the coagulation system, and the risks of thrombosis. Thus, more biologically- based, disease-specific and personalized approaches may be needed to diagnose and manage cancer-related thrombosis.

Mechanisms coupling thrombin to metastasis and tumorigenesis

The association of malignancy and thrombophilia is bidirectional, as evidenced by four decades of studies in animal models showing that hemostatic system components support cancer progression. Consistent with this view, clinical studies have suggested that anticoagulants not only limit thromboembolic complications associated with cancer, but also improve survival by impeding cancer progression, and may even prevent the development of cancer. In order to fully capitalize on this association, a detailed understanding of the mechanisms coupling hemostatic factors to cancer pathogenesis is required. Multiple studies have shown that thrombin-mediated procoagulant functions strongly promote metastatic potential. In particular, the platelet/fibrin(ogen) axis has been shown to protect newly formed micrometastases from innate immune surveillance, contribute to creation of a metastatic niche by recruitment of prometastatic inflammatory cells, and promote the epithelial to mesenchymal transition of metastatic cells. Thrombin-mediated functions have also been shown to support tumor growth in some contexts, and have even been linked to tumorigenesis in the setting of inflammation-driven colon cancer. Here, local thrombin-mediated extravascular fibrin deposition, and specifically fibrin-α_Mβ₂ integrin interaction, push intestinal inflammatory cells toward a pro-tumorigenic phenotype, resulting in the elaboration of key cytokines and growth factors that support the proliferation and survival of transformed intestinal epithelial cells. These studies reveal that hemostatic factors can serve as a bridge between pathological inflammation and the development of cancer. As a large proportion of cancers are caused by pathological inflammation, these studies suggest that therapies targeting the nexus between hemostasis and inflammation could be used to prevent cancer development.

Cancer-associated thrombosis: The search for the holy grail continues

Cancer patients have an increased risk of developing venous thromboembolism (VTE), a condition that is associated with increased morbidity and mortality. Although risk assessment tools have been developed, it is still very challenging to predict which cancer patients will suffer from VTE. The scope of this review is to summarize and discuss studies focusing on the link between genetic alterations and risk of cancer-associated thrombosis (CAT). Thus far, classical risk factors that contribute to VTE have been tried as risk factors of CAT, with low success. In support, hypercoagulant plasma profiles in patients with CAT differ from those with only VTE, indicating other risk factors that contribute to VTE in cancer. As germline mutations do not significantly contribute to elevated risk of VTE, somatic mutations in tumors may significantly associate with and contribute to CAT. As it is very time-consuming to investigate each and every mutation, an unbiased approach is warranted. In this light we discuss our own recent unbiased proof-of-principle study using RNA sequencing in isolated colorectal cancer cells. Our work has uncovered candidate genes that associate with VTE in colorectal cancer, and these gene profiles associated with VTE more significantly than classical parameters such as platelet counts, D-dimer, and P-selectin levels. Genes associated with VTE could be linked to pathways being involved in coagulation, inflammation and methionine degradation. We conclude that tumor cell-specific gene expression profiles and/or mutational status has superior potential as predictors of VTE in cancer patients.

Methylation-dependent Tissue Factor Suppression Contributes to the Reduced Malignancy of IDH1-mutant Gliomas

PURPOSE

Gliomas with isocitrate dehydrogenase 1 mutations (IDH1^mut) are less aggressive than IDH1 wild-type (IDH1^wt) gliomas and have global genomic hypermethylation. Yet it is unclear how specific hypermethylation events contribute to the IDH1^mut phenotype. Previously, we showed that the gene encoding the procoagulant tissue factor (TF), F3, is among the most hypermethylated and downregulated genes in IDH1^mut gliomas, correlating with greatly reduced thrombosis in patients with IDH1^mut glioma. Because TF also increases the aggressiveness of many cancers, the current study explored the contribution of TF suppression to the reduced malignancy of IDH1^mut gliomas.Experimental Design: TF expression was manipulated in patient-derived IDH1^mut and IDH1^wt glioma cells, followed by evaluation of in vitro and in vivo behavior and analyses of cell signaling pathways.

RESULTS

A demethylating agent, decitabine, increased F3 transcription and TF-dependent coagulative activity in IDH1^mut cells, but not in IDH1^wt cells. TF induction enhanced the proliferation, invasion, and colony formation of IDH1^mut cells, and increased the intracranial engraftment of IDH1^mut GBM164 from 0% to 100% (P = 0.0001). Conversely, TF knockdown doubled the median survival of mice engrafted with IDH1^wt/EGFRvIII^amp GBM6, and caused complete regression of IDH1^wt/EGFR^amp GBM12 (P = 0.001). In vitro and in vivo effects were linked to activation of receptor tyrosine kinases (RTK) by TF through a Src-dependent intracellular pathway, even when extracellular RTK stimulation was blocked. TF stimulated invasion predominately through upregulation of β-catenin.

CONCLUSIONS

These data show that TF suppression is a component of IDH1^mut glioma behavior, and that it may therefore be an attractive target against IDH1^wt gliomas.

Treating Tissue Factor-Positive Cancers with Antibody-Drug Conjugates That Do Not Affect Blood Clotting

The primary function of tissue factor (TF) resides in the vasculature as a cofactor of blood clotting; however, multiple solid tumors aberrantly express this transmembrane receptor on the cell surface. Here, we developed anti-TF antibody-drug conjugates (ADC) that did not interfere with the coagulation cascade and benchmarked them against previously developed anti-TF ADCs. After screening an affinity-matured antibody panel of diverse paratopes and affinities, we identified one primary paratope family that did not inhibit conversion of Factor X (FX) to activated Factor X (FXa) and did not affect conversion of prothrombin to thrombin. The rest of the antibody panel and previously developed anti-TF antibodies were found to perturb coagulation to varying degrees. To compare the anticancer activity of coagulation-inert and -inhibitory antibodies as ADCs, a selection of antibodies was conjugated to the prototypic cytotoxic agent monomethyl auristatin E (MMAE) through a protease-cleavable linker. The coagulation-inert and -inhibitory anti-TF ADCs both killed cancer cells effectively. Importantly, the coagulation-inert ADCs were as efficacious as tisotumab vedotin, a clinical stage ADC that affected blood clotting, including in patient-derived xenografts from three solid tumor indications with a need for new therapeutic treatments-squamous cell carcinoma of the head and neck (SCCHN), ovarian, and gastric adenocarcinoma. Furthermore, a subset of the anti-TF antibodies could also be considered for the treatment of other diseases associated with upregulation of membranous TF expression, such as macular degeneration. Mol Cancer Ther; 17(11); 2412-26. ©2018 AACR.

Positive crosstalk between EGFR and the TF-PAR2 pathway mediates resistance to cisplatin and poor survival in cervical cancer

Cisplatin-based chemoradiation is the standard treatment for cervical cancer, but chemosensitizing strategies are needed to improve patient survival. EGFR (Epidermal Growth Factor Receptor) is an oncogene overexpressed in cervical cancer that is involved in chemoresistance. Recent studies showed that EGFR upregulates multiple elements of the coagulation cascade, including tissue factor (TF) and the protease-activated receptors (PAR) 1 and 2. Moreover, many G protein-coupled receptors, including PARs, have been implicated in EGFR transactivation. However, the role of coagulation proteins in the progression of cervical cancer has been poorly investigated. Herein we employed cervical cancer cell lines and The Cancer Genome Atlas (TCGA) database to evaluate the role of EGFR, TF and PAR2 in chemoresistance. The SLIGKL-NH2 peptide (PAR2-AP) and coagulation factor VIIa (FVIIa) were used as PAR2 agonists, while cetuximab was used to inhibit EGFR. The more aggressive cell line CASKI showed higher expression levels of EGFR, TF and PAR2 than that of C33A. PAR2 transactivated EGFR, which further upregulated cyclooxygenase-2 (COX2) expression. PAR2-AP decreased cisplatin-induced apoptosis through an EGFR- and COX2-dependent mechanism. Furthermore, treatment of CASKI cells with EGF upregulated TF expression, while treatment with cetuximab decreased the TF protein levels. The RNA-seq data from 309 TCGA samples showed a strong positive correlation between EGFR and TF expression (P = 0.0003). In addition, the increased expression of EGFR, PAR2 or COX2 in cervical cancer patients was significantly correlated with poor overall survival. Taken together, our results suggest that EGFR and COX2 are effectors of the TF/FVIIa/PAR2 signaling pathway, promoting chemoresistance.

Identification of key pathways and biomarkers in sorafenib-resistant hepatocellular carcinoma using bioinformatics analysis

Hepatocellular carcinoma (HCC) is one of the most common malignant types of cancer, with a high mortality rate. Sorafenib is the sole approved oral clinical therapy against advanced HCC. However, individual patients exhibit varying responses to sorafenib and the development of sorafenib resistance has been a new challenge for its clinical efficacy. The current study identified gene biomarkers and key pathways in sorafenib-resistant HCC using bioinformatics analysis. Gene dataset GSE73571 was obtained from the Gene Expression Omnibus (GEO) database, including four sorafenib-acquired resistant and three sorafenib-sensitive HCC phenotypes. Differentially expressed genes (DEGs) were identified using the web tool GEO2R. Functional and pathway enrichment of DEGs were analyzed using the Database for Annotation, Visualization and Integrated Discovery and the protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins and Cytoscape. A total of 1,319 DEGs were selected, which included 593 upregulated and 726 downregulated genes. Functional and pathway enrichment analysis revealed DEGs enriched in negative regulation of endopeptidase activity, cholesterol homeostasis, DNA replication and repair, coagulation cascades, insulin resistance, RNA transport, cell cycle and others. Eight hub genes, including kininogen 1, vascular cell adhesion molecule 1, apolipoprotein C3, alpha 2-HS glycoprotein, erb-b2 receptor tyrosine kinase 2, secreted protein acidic and cysteine rich, vitronectin and vimentin were identified from the PPI network. In conclusion, the present study identified DEGs and key genes in sorafenib-resistant HCC, which further the knowledge of potential mechanisms in the development of sorafenib resistance and may provide potential targets for early diagnosis and new treatments for sorafenib-resistant HCC.

Advances in Diagnostic and Intraoperative Molecular Imaging of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. To improve outcomes, there is a critical need for improved tools for detection, accurate staging, and resectability assessment. This could improve patient stratification for the most optimal primary treatment modality. Molecular imaging, used in combination with tumor-specific imaging agents, can improve established imaging methods for PDAC. These novel, tumor-specific imaging agents developed to target specific biomarkers have the potential to specifically differentiate between malignant and benign diseases, such as pancreatitis. When these agents are coupled to various types of labels, this type of molecular imaging can provide integrated diagnostic, noninvasive imaging of PDAC as well as image-guided pancreatic surgery. This review provides a detailed overview of the current clinical imaging applications, upcoming molecular imaging strategies for PDAC, and potential targets for imaging, with an emphasis on intraoperative imaging applications.

Influence of the dissociation rate constant on the intra-tumor distribution of antibody-drug conjugate against tissue factor

Antibody-drug conjugates (ADCs) are currently considered to be promising agents for cancer therapy. However, especially in solid tumors, the uneven distribution of ADCs would decrease their efficacy in clinical studies. We suggest that in addition to optimizing ADC components, such as the linker structure and anticancer agent, it is necessary to consider the distribution of the ADC within tumor tissue. In this study, we established three kinds of anti-tissue factor (TF) ADCs: 1849ADC with a low k_d, 444ADC with an intermediate k_d, and 1084ADC with a high k_d. All three of the anti-TF ADCs exhibited almost the same in vitro cytotoxicity and pharmacological and biochemical characteristics, although the binding kinetics parameters differed. In vivo, all ADCs exerted equivalent antitumor effects against small BxPC3 tumors. However, on larger BxPC3 tumors, 1084ADC (higher k_d) exerted higher antitumor activity than 1849ADC (lower k_d). Furthermore, immunofluorescence staining indicated that 1084ADC was distributed throughout the whole tumor, whereas 1849ADC was mainly localized close to tumor vessels. We conclude that the ADC with a higher k_d increased the antitumor effect of because it penetrated and distributed evenly throughout the entire solid tumor. These findings highlight the importance of the k_d of a mAb in ADC design.

Tissue factor mediates microvesicles shedding from MDA-MB-231 breast cancer cells

Extracellular vesicles, such as microvesicles (MVs), were identified as important players in tumor progression and acquisition of an aggressive phenotype. Tissue factor (TF) is a transmembrane protein that initiates the blood coagulation cascade. In tumor cells, TF has been associated with aggressiveness and cancer progression. Previous studies demonstrate that TF is incorporated into MVs secreted by tumor cells; however, it is unknown whether TF is actively involved in the release of MVs. Here, we investigated the influence of TF expression on the release of MVs. TF silencing was achieved through CRISPR/Cas9 approaches in the human breast cancer cell line, MDA-MB-231. TF knockout in MDA-MB-231 cells efficiently reduced TF-dependent signaling and procoagulant activity. Remarkably, silencing of TF caused a significant decrease in the number of MVs released by MDA-MB-231 cells. We also observed an increase in actin-positive membrane projections in TF knockout cells and a reduction in RhoA expression when compared to TF-expressing cells. Treatment of MDA-MB-231 cells with the RhoA-ROCK signaling pathway inhibitor, fasudil, significantly reduced the release of MVs. Taken together, our results suggest a novel and relevant role for TF in tumor biology by playing an active role in the MVs secretion.

Tumor-Derived Apoptotic Vesicles: With Death They Do Part

Tumor cells release lipid particles known as extracellular vesicles (EV) that contribute to cancer metastasis, to the immune response, and to thrombosis. When tumors are exposed to radiation or chemotherapy, apoptotic vesicles (ApoVs) are released in abundance as the plasma membrane delaminates from the cytoskeleton. Recent studies have suggested that ApoVs are distinct from the EVs released from living cells, such as exosomes or microvesicles. Depending on their treatment conditions, tumor-released ApoV have been suggested to either enhance or suppress anti-cancer immunity. In addition, tumor-derived ApoV possess procoagulant activity that could increase the thrombotic state in cancer patients undergoing chemotherapy or radiotherapy. Since ApoVs are one of the least appreciated type of EVs, we focus in this review on the distinctive characterization of tumor ApoVs and their proposed mechanistic effects on cancer immunity, coagulation, and metastasis.

Factor VIIa induces anti-inflammatory signaling via EPCR and PAR1

Recent studies show that endothelial cell protein C receptor (EPCR) interacts with diverse ligands, in addition to its known ligands protein C and activated protein C (APC). We showed in earlier studies that procoagulant clotting factor VIIa (FVIIa) binds EPCR and downregulates EPCR-mediated anticoagulation and induces an endothelial barrier protective effect. Here, we investigated the effect of FVIIa's interaction with EPCR on endothelial cell inflammation and lipopolysaccharide (LPS)-induced inflammatory responses in vivo. Treatment of endothelial cells with FVIIa suppressed tumor necrosis factor α (TNF-α)- and LPS-induced expression of cellular adhesion molecules and adherence of monocytes to endothelial cells. Inhibition of EPCR or protease-activated receptor 1 (PAR1) by either specific antibodies or small interfering RNA abolished the FVIIa-induced suppression of TNF-α- and LPS-induced expression of cellular adhesion molecules and interleukin-6. β-Arrestin-1 silencing blocked the FVIIa-induced anti-inflammatory effect in endothelial cells. In vivo studies showed that FVIIa treatment markedly suppressed LPS-induced inflammatory cytokines and infiltration of innate immune cells into the lung in wild-type and EPCR-overexpressing mice, but not in EPCR-deficient mice. Mechanistic studies revealed that FVIIa treatment inhibited TNF-α-induced ERK1/2, p38 MAPK, JNK, NF-κB, and C-Jun activation indicating that FVIIa-mediated signaling blocks an upstream signaling event in TNFα-induced signaling cascade. FVIIa treatment impaired the recruitment of TNF-receptor-associated factor 2 into the TNF receptor 1 signaling complex. Overall, our present data provide convincing evidence that FVIIa binding to EPCR elicits anti-inflammatory signaling via a PAR1- and β-arrestin-1 dependent pathway. The present study suggests new therapeutic potentials for FVIIa, which is currently in clinical use for treating bleeding disorders.

Advances in Clinical and Basic Science of Coagulation: Illustrated abstracts of the 9th Chapel Hill Symposium on Hemostasis

This 9th Symposium on Hemostasis is an international scientific meeting held biannually in Chapel Hill, North Carolina. The meeting is in large measure the result of the close friendship between the late Dr. Harold R. Roberts of UNC Chapel Hill and Dr. Ulla Hedner of Novo Nordisk. When Novo Nordisk was developing the hemophilia therapy that would become NovoSeven, they sponsored a series of meetings to understand the basic biology and clinical applications of factor VIIa. The first meeting in Chapel Hill was held April 4-6, 2002 with Dr. Roberts as the organizer. Over the years, the conference emphasis has expanded from discussions of factor VIIa and tissue factor to additional topics in hemostasis and thrombosis. This year's meeting includes presentations by internationally renowned speakers that discuss the state-of-the-art on an array of important topics, including von Willebrand factor, engineering advances, coagulation and disease, tissue factor biology, therapeutic advances, and basic clotting factor biology. Included in this review article are illustrated abstracts provided by our speakers, which highlight the main conclusions of each invited talk. This will be the first meeting without Dr. Roberts in attendance, yet his commitment to excellent science and his focus on turning science to patient care are pervasively reflected in the presentations by our speakers.

Antibody fragment-conjugated gemcitabine and paclitaxel-based liposome for effective therapeutic efficacy in pancreatic cancer

In this study, we have developed an antibody fragment (AF)-conjugated gemcitabine (GEM) and paclitaxel (PTX)-loaded liposome (AF-GPL) to enhance the therapeutic efficacy in pancreatic cancer treatment. The maleimide-thiol chemistry was utilized to conjugate AF on the liposome surface. The dual-drug loaded liposome was nanosized and exhibited a controlled release of both the drugs. Importantly, two drugs have different release pattern over a period of time. The AF-conjugated liposome showed enhanced cellular uptake in pancreatic cancer cells compared to that of non-targeted liposome. Two-fold higher internalization of particles might increase the intracellular concentration of anticancer drugs that might further increase the therapeutic efficacy in pancreatic cancer cells. AF-GPL showed significantly higher cytotoxic effect in pancreatic cancer cell compared to that of non-targeted GPL. The IC50 value of GEM, PTX, GPL and AF-GPL were 5.9 μg/ml, 4.2 μg/ml, 1.92 μg/ml, and 0.45 μg/ml, respectively. Consistently, AF-GPL (4.12) showed significantly higher ratio of Bax/Bcl-2 compared to that of non-targeted GPL (2.8). Importantly, AF-GPL induced a significant apoptosis of cancer cells with predominant amount of cells in late apoptosis cells. Overall, AF-conjugated nanosystem could potentially improve the therapeutic efficacy in pancreatic cancers.

Extracellular vesicles exposing tissue factor for the prediction of venous thromboembolism in patients with cancer: A prospective cohort study

INTRODUCTION

The procoagulant activity of extracellular vesicles (EV) exposing tissue factor (TF) is a promising biomarker for venous thromboembolism (VTE) in cancer patients. We evaluated an in-house EV-TF activity assay (the fibrin generation test) for the prediction of cancer-associated VTE. We also compared the results with the fibrin generation tests to an EV-TF-dependent factor Xa generation assay in samples from pancreatic cancer patients.

MATERIALS AND METHODS

Data collected in a multinational, prospective cohort study were used. Patients with various types of advanced cancer were enrolled if chemotherapy was scheduled or started in the previous 3 months. Patients were followed for 6 months for the occurrence of VTE. The fibrin generation test was performed at baseline to measure EV-TF procoagulant activity.

RESULTS

The fibrin generation test was performed in 648 patients with advanced cancer. The mean age was 62 years; 58% had distant metastasis. Forty patients (6.1%) developed VTE. Overall, a high fibrin generation test result was associated with a two-fold increased risk for VTE (HR 2.0; 95%-CI, 1.1-3.6). The association was stronger in patients with pancreatic cancer (HR 4.1; 95%-CI, 0.91-19) than in those with other tumor types (HR 1.5; 95%-CI, 0.72-3.1). Correlation between the FGT and the TF-dependent factor Xa generation assay in patients with pancreatic cancer was poor (Spearman's R = 0.35).

CONCLUSION

This study shows that a high EV-TF procoagulant activity as measured by the fibrin generation test is associated with an increased risk of VTE in cancer patients, in particular in those with pancreatic cancer. Future studies should aim to further improve the feasibility and accuracy of EV-TF activity assays.

Comprehensive analysis of haemostatic profile depending on clinicopathological determinants in breast cancer patients

Thrombosis is one of the leading causes of mortality in cancer patients. The aim of the study was to evaluate the concentrations and activities of selected haemostatic parameters in the plasma of patients diagnosed with breast cancer (BrCa) and to make an attempt at finding associations with their levels and selected clinicopathological factors; clinical classification, histological grading, and molecular subtype of BrCa. The study involved 145 Caucasian ethnicity women. Eighty-five women aged 45-66 with primary BrCa without distant metastases (M0). Inclusion criteria were as follows: histopathological examination confirming the diagnosis of primary BrCa, without previous radiotherapy and chemotherapy. The control group consisted of 60, post-menopausal women, aged 45-68. Haemostatic profile expressed by concentrations and activities of tissue factor (TF) and its inhibitor (TFPI) as well as concentrations of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) were measured applying immunoassay techniques. A significantly higher concentration of PAI-1 was noted in patients with BrCa localized in the left breast. We observed significantly lower activity of TFPI and significantly higher concentration of PAI-1 in the group of patients with invasive ductal carcinoma as compared with invasive lobular carcinoma. A significantly higher concentration of t-PA in patients with pT2 BrCa in relation to pT1 cases was noted. Based on comprehensive analysis of haemostatic profile depending on clinicopathological features, we suggest that haemostatic parameters play crucial roles in invasion and metastases of malignant tumours.

The coagulome and the oncomir: impact of cancer-associated haemostatic dysregulation on the risk of metastasis

Patients with cancer are at high risk of both thromboembolic and haemorrhagic events during the course of their disease. The pathogenesis of haemostatic dysfunction in cancer is complex and involves the interplay of multiple factors. There is growing evidence that interactions between malignancies and the coagulation system are not random but can represent coordinated and clinically-significant adaptations that enhance tumour cell survival, proliferation and metastatic potential. A detailed understanding of the interactions between the haemostatic systems and the pathophysiology of metastasis may not only provide insight into strategies that could potentially reduce the incidence of thrombohaemorrhagic events and complications, but could also help design strategies that are capable of modifying tumour biology, progression and metastatic potential in ways that could enhance anticancer therapies and thereby improve overall survival.

Dynamic MR imaging for functional vascularization depends on tissue factor signaling in glioblastoma

Glomeruloid vascular proliferation (GVP) is a diagnostic hallmark and links to aggressive behavior, therapy resistance and poor prognosis in glioblastoma (GBM). It lacks clinical approaches to predict and monitor its formation and dynamic change. Yet the mechanism of GVPs also remains largely unknown. Using an in situ GBM xenograft mouse model, combined clinical MRI images of pre-surgery tumor and pathological investigation, we demonstrated that the inhibition of tissue factor (TF) decreased GVPs in Mouse GBM xenograft model. TF shRNA reduced microvascular area and diameter, other than bevacizumab. TF dominantly functions via PAR2/HB-EGF-dependent activation under hypoxia in endothelial cells (ECs), resulting in a reduction of GVPs and cancer cells invasion. TF expression strongly correlated to GVPs and microvascular area (MVA) in GBM specimens from 56 patients, which could be quantitatively evaluated in an advanced MRI images system in 33 GBM patients. This study presented an approach to assess GVPs that could be served as a MRI imaging biomarker in GBM and uncovered a molecular mechanism of GVPs.

Positively selected enhancer elements endow osteosarcoma cells with metastatic competence

Metastasis results from a complex set of traits acquired by tumor cells, distinct from those necessary for tumorigenesis. Here, we investigate the contribution of enhancer elements to the metastatic phenotype of osteosarcoma. Through epigenomic profiling, we identify substantial differences in enhancer activity between primary and metastatic human tumors and between near isogenic pairs of highly lung metastatic and nonmetastatic osteosarcoma cell lines. We term these regions metastatic variant enhancer loci (Met-VELs). Met-VELs drive coordinated waves of gene expression during metastatic colonization of the lung. Met-VELs cluster nonrandomly in the genome, indicating that activity of these enhancers and expression of their associated gene targets are positively selected. As evidence of this causal association, osteosarcoma lung metastasis is inhibited by global interruptions of Met-VEL-associated gene expression via pharmacologic BET inhibition, by knockdown of AP-1 transcription factors that occupy Met-VELs, and by knockdown or functional inhibition of individual genes activated by Met-VELs, such as that encoding coagulation factor III/tissue factor (F3). We further show that genetic deletion of a single Met-VEL at the F3 locus blocks metastatic cell outgrowth in the lung. These findings indicate that Met-VELs and the genes they regulate play a functional role in metastasis and may be suitable targets for antimetastatic therapies.

Antibody-based targeting of alternatively spliced tissue factor: a new approach to impede the primary growth and spread of pancreatic ductal adenocarcinoma

Alternatively spliced Tissue Factor (asTF) is a secreted form of Tissue Factor (TF), the trigger of blood coagulation whose expression levels are heightened in several forms of solid cancer, including pancreatic ductal adenocarcinoma (PDAC). asTF binds to β1 integrins on PDAC cells, whereby it promotes tumor growth, metastatic spread, and monocyte recruitment to the stroma. In this study, we determined if targeting asTF in PDAC would significantly impact tumor progression. We here report that a novel inhibitory anti-asTF monoclonal antibody curtails experimental PDAC progression. Moreover, we show that tumor-derived asTF is able to promote PDAC primary growth and spread during early as well as later stages of the disease. This raises the likelihood that asTF may comprise a viable target in early- and late-stage PDAC. In addition, we show that TF expressed by host cells plays a significant role in PDAC spread. Together, our data demonstrate that targeting asTF in PDAC is a novel strategy to stem PDAC progression and spread.

Site-Specific 64Cu Labeling of the Serine Protease, Active Site Inhibited Factor Seven Azide (FVIIai-N3), Using Copper Free Click Chemistry

A method for site-specific radiolabeling of the serine protease active site inhibited factor seven (FVIIai) with ⁶⁴Cu has been applied using a biorthogonal click reaction. FVIIai binds to tissue factor (TF), a trans-membrane protein involved in hemostasis, angiogenesis, proliferation, cell migration, and survival of cancer cells. First a single azide moiety was introduced in the active site of this 50 kDa protease. Then a NOTA moiety was introduced via a strain promoted azide-alkyne reaction and the corresponding conjugate was labeled with ⁶⁴Cu. Binding to TF and the stability was evaluated in vitro. TF targeting capability of the radiolabeled conjugate was tested in vivo by positron emission tomography (PET) imaging in pancreatic human xenograft cancer mouse models with various TF expressions. The conjugate showed good stability (>91% at 16 h), an immunoreactivity of 93.5%, and a mean tumor uptake of 2.1 ± 0.2%ID/g at 15 h post injection. In conclusion, FVIIai was radiolabeled with ⁶⁴Cu in single well-defined position of the protein. This method can be utilized to prepare conjugates from serine proteases with the label at a specific position.

Tissue Factor-Expressing Tumor-Derived Extracellular Vesicles Activate Quiescent Endothelial Cells via Protease-Activated Receptor-1

Tissue factor (TF)-expressing tumor-derived extracellular vesicles (EVs) can promote metastasis and pre-metastatic niche formation, but the mechanisms by which this occurs remain largely unknown. We hypothesized that generation of activated factor X (FXa) by TF expressed on tumor-derived EV could activate protease-activated receptors (PARs) on non-activated endothelial cells to induce a pro-adhesive and pro-inflammatory phenotype. We obtained EV from TF-expressing breast (MDA-MB-231) and pancreatic (BxPC3 and Capan-1) tumor cell lines. We measured expression of E-selectin and secretion of interleukin-8 (IL-8) in human umbilical vein endothelial cells after exposure to EV and various immunologic and chemical inhibitors of TF, FXa, PAR-1, and PAR-2. After 6 h of exposure to tumor-derived EV (pretreated with factor VIIa and FX) in vitro, endothelial cells upregulated E-selectin expression and secreted IL-8. These changes were decreased with an anti-TF antibody, FXa inhibitors (FPRCK and EGRCK), and PAR-1 antagonist (E5555), demonstrating that FXa generated by TF-expressing tumor-derived EV was signaling through endothelial PAR-1. Due to weak constitutive PAR-2 expression, these endothelial responses were not induced by a PAR-2 agonist peptide (SLIGKV) and were not inhibited by a PAR-2 antagonist (FSLLRY) after exposure to tumor-derived EV. In conclusion, we found that TF-expressing cancer-derived EVs activate quiescent endothelial cells, upregulating E-selectin and inducing IL-8 secretion through generation of FXa and cleavage of PAR-1. Conversion of resting endothelial cells to an activated phenotype by TF-expressing cancer-derived EV could promote cancer metastases.

Metastatic pathway and the microvascular and physicochemical microenvironments of human melanoma xenografts

BACKGROUND

Malignant melanoma of the skin can metastasize through blood vessels and lymphatics. The primary tumor develops a vascular microenvironment characterized by abnormal blood vessels and lymphatics and a physicochemical microenvironment characterized by low oxygen tension, regions with hypoxic tissue, and high interstitial fluid pressure (IFP). This study aimed at identifying relationships between the metastatic route of melanomas and characteristic features of the microvascular and physicochemical microenvironments of the primary tumor.

METHODS

Two patient-derived xenograft (PDX) models (E-13, N-15) and four cell line-derived xenografts (CDX) models (C-10, D-12, R-18, T-22) of human melanoma were included in the study. Tumors were transplanted to an orthotopic site in BALB/c-nu/nu mice, and when the tumors had grown to a volume of 500-600 mm3, the IFP of the primary tumor was measured and the hypoxia marker pimonidazole was administered before the host mouse was euthanized. The primary tumor, lungs, and six pairs of lymph nodes were evaluated by examining hematoxylin/eosin-stained and immunostained histological preparations. The expression of angiogenesis-related genes was assessed by quantitative PCR.

RESULTS

C-10, D-12, and E-13 tumors disseminated primarily by the hematogenous route and developed pulmonary metastases. These tumors showed high angiogenic activity and high expression of the F3 gene as well as ANGPT2 and TIE1, genes encoding proteins of the angiopoietin-tie system. N-15, R-18, and T-22 tumors disseminated mainly by the lymphogenous route and developed metastases in draining lymph nodes. These tumors had highly elevated IFP and showed high expression of NRP2, a gene encoding neuropilin-2.

CONCLUSION

The primary metastatic route of orthotopic human melanoma xenografts and the development of lung and lymph node metastases are influenced significantly by the microvascular and physicochemical microenvironments of the primary tumor.

Circulating tumor cell count and thrombosis in metastatic breast cancer

Essentials Tumor cells circulating in blood (CTC) may favor thrombotic events in cancer patients. We assessed the impact of CTC on the risk of thrombosis in metastatic breast cancer. Baseline CTC detection was the only independent factor associated with the risk of thrombosis. CTC detection under therapy may be the hidden link between tumor progression & thrombosis.

SUMMARY

Background Circulating tumor cell (CTC) count is a major prognostic factor in metastatic breast cancer (MBC) and has been reported to be associated with thrombosis in short-term studies on MBC patients. Objective To assess whether CTC detection (CellSearch® ) before first-line chemotherapy impacts the risk of thrombosis throughout the course of MBC. Patients/Methods Among patients included before first-line chemotherapy for MBC in the prospective IC2006-04 CTC detection study (NCT00898014), the electronic medical files of those patients treated at Institut Curie (Paris, France) were searched in silico and manually checked for incident venous or arterial thrombotic events (TE) in the course of MBC. Univariate and multivariate analyses were performed using Cox and Fine-Gray models, adjusted for age and Khorana score. Results/Conclusions With a median follow-up of 64 months (25-81 months), among the 142 patients included, 34 (24%) experienced a TE (incidence rate, 8 TE/100 patient-years). The TE incidence rate was 13 TE/100 patient-years for the 80 patients with ≥ 1 CTC/7.5 mL of blood before initiating first-line chemotherapy, vs. only 4 TE/100 patient-years for the 62 CTC-negative patients. Fine-Gray multivariate analysis (with death as competing event) included age, Khorana score and baseline lactate dehydrogenase and CTC levels: detectable CTC was the only factor significantly associated with an increased risk of TE (sub-distribution hazard ratio [SHR] for patients with [1-4] CTC = 3.1, 95% CI [1.1; 8.6], SHR for patients with ≥ 5 CTC = 1.4, 95% CI [0.5; 4.6]). This study shows that CTC detection before starting first-line chemotherapy is an independent risk factor for TE in MBC patients.

Molecular imaging using an anti-human tissue factor monoclonal antibody in an orthotopic glioma xenograft model

Nuclear medicine examinations for imaging gliomas have been introduced into clinical practice to evaluate the grade of malignancy and determine sampling locations for biopsies. However, these modalities have some limitations. Tissue factor (TF) is overexpressed in various types of cancers, including gliomas. We thus generated an anti-human TF monoclonal antibody (mAb) clone 1849. In the present study, immunohistochemistry performed on glioma specimens using anti-TF 1849 mAb showed that TF expression in gliomas increased in proportion to the grade of malignancy based on the World Health Organization (WHO) classification, and TF was remarkably expressed in necrosis and pseudopalisading cells, the histopathological hallmarks of glioblastoma multiforme (GBM). Furthermore, in both fluorescence and single-photon emission computed tomography/computed tomography (SPECT/CT) imaging studies, anti-TF 1849 IgG efficiently accumulated in TF-overexpressing intracranial tumours in mice. Although further investigation is required for a future clinical use of immuno-SPECT with ¹¹¹In-labelled anti-TF 1849 IgG, the immuno-SPECT may represent a unique imaging modality that can visualize the biological characteristics of gliomas differently from those obtained using the existing imaging modalities and may be useful to evaluate the grade of malignancy and determine sampling locations for biopsies in patients with glioma, particularly GBM.

In Surgical Colon Cancer Patients Extended-Duration Thromboprophylaxis (30 days) with the Highest Dose of Tinzaparin (4,500 IU s.c./q.d.) Normalizes the Postoperative VEGF Levels

Background/Purpose: In colon cancer (CC) patients preoperative (pre-op) levels of VEGF-A₁₆₅ (VEGF) is a strong predictor for disease recurrence. Elevated postoperative (post-op) VEGF levels could have undesirable effects by enhancing tumor growth and metastasis formation. It has been suggested that thromboprophylaxis with a Low Molecular Weight Heparin (LMWH) in surgical cancer patients, further to thromboembolic protection, may exert some anti-neoplastic properties, as well. The aim of our study was to assess the potential impact of the LMWH Tinzaparin (Innohep® - Leo Pharma, Copenhagen, Denmark), given at different doses and for different perioperative (peri-op) periods, upon the post-op variability of serum VEGF levels in surgical CC patients. Methods: A total of 54 consecutive CC patients who underwent a curative resection were randomized in four groups according to their peri-op thromboprophylaxis scheme, which was based on administrating Tinzaparin in different doses and at different periods, as follows: group I: 3,500 IU for 10 days, group II: 3,500 IU for 30 days, group III: 4,500 IU for 10 days and group IV: 4,500 IU for 30 days. Serum VEGF concentrations were evaluated on the pre-op day (Day 0) and on the 10^th and 30^th post-op days (Day 10 and Day 30, respectively). For statistical analyses the mixed design ANOVA was used. P < 0.05 was considered significant. Results: On Day 0, VEGF didn't differ between groups I, II, III and IV (p>0.05, for every comparison). On Day 10, VEGF was increased in all groups. Between Day 10 and Day 30, VEGF remained stable in groups I (p=0.031) and II (p=1.000) and increased significantly in group III (p=0.005). On the contrary, VEGF decreased significantly in group IV (p<0.001). The most remarkable finding was observed when we compared VEGF between Day 0 and Day 30: while in groups I, II and III, VEGF remained significantly higher compared to Day 0 (p<0.001, p=0.041 and p<0.001, respectively), on the contrary, in group IV (extended-duration with the highest dose of 4,500 IU of tinzaparin) it was comparable to Day 0 (p=1.000). Conclusions: In surgical CC patients only the recommended thromboprophylaxis scheme with the highest prophylactic dose of Tinzaparin (4,500 IU) for extended-duration (30 days) normalizes VEGF levels at the end of the first post-op month by reducing them to the pre-op levels.

Thromboembolisms in Advanced Pancreatic Cancer: A Retrospective Analysis of 475 Patients

OBJECTIVES

Pancreatic cancer is reported to be highly associated with thromboembolism (TE). The aim of this analysis is to clarify risk factors for TE and its clinical impact in Japanese patients with pancreatic cancer.

METHODS

Data on consecutive pancreatic cancer patients receiving systemic chemotherapy between August 1999 and July 2015 were retrospectively studied. Both symptomatic and asymptomatic, arterial and venous TEs were included in the analysis. Risk factors for TE development were analyzed using a proportional hazards model with death without TE as a competing risk. The impact of TE on survival was also evaluated using a time-dependent covariate multiple Cox model.

RESULTS

A total of 475 patients were included in the analysis, and 57 TEs (12%) were identified: 45 venous TEs and 12 arterial TEs. The median time to TE was 169 days and the median survival from TE was 65 days. Liver metastasis was the only significant risk factor for TE (subdistribution hazards ratio, 2.15; P = 0.01), and TE was significantly associated with poor prognosis (hazards ratio, 3.31; P < 0.01).

CONCLUSIONS

Thromboembolism was not uncommon in Japanese patients receiving chemotherapy for advanced pancreatic cancer and was associated with poor prognosis. Liver metastasis was the risk factor for TE.

Urokinase-type plasminogen activator receptor (uPAR), tissue factor (TF) and epidermal growth factor receptor (EGFR): tumor expression patterns and prognostic value in oral cancer

Background

Tumor-specific biomarkers are a prerequisite for the development of targeted imaging and therapy in oral squamous cell carcinoma (OSCC). urokinase-type Plasminogen Activator Receptor (uPAR), Tissue Factor (TF) and Epidermal Growth Factor Receptor (EGFR) are three biomarkers that exhibit enhanced expression in many types of cancers, and have been investigated as potential biomarkers for targeted strategies and prognostication. The aim of the study was to investigate the expression patterns of uPAR, TF and EGFR and their potential prognostic value in OSCC.

Methods

Immunohistochemical expression of uPAR, TF and EGFR in tumor resection specimens from 191 patients with primary OSCC was analyzed. Overall (OS) and disease-free survival (DFS) was calculated. Associations between biomarker expression, clinicopathological factors and patient survival was analyzed using the Cox proportional hazards model for univariate and multivariate analysis, log rank and Kaplan-Meier statistics.

Results

uPAR and TF exhibited a highly tumor-specific expression pattern while EGFR also showed expression in normal tissues outside the tumor compartment. The overall positive expression rate of uPAR, TF and EGFR was 95%, 58% and 98%, respectively. High uPAR expression across the entire cohort was negatively associated with OS (p = 0.031, HR = 1.595 (95%CI 1.044–2.439)) in univariate analysis. The 5-year OS for high and low uPAR expression was 39% and 56%, respectively. The expression of TF and EGFR was not associated with survival outcome.

Conclusions

This study may suggest that uPAR and TF could potentially be attractive targets for molecular imaging and therapy in OSCC due to high positive expression rates and tumor-specific expression patterns. High uPAR expression was significantly associated with a reduced survival. uPAR seems to be a prognostic biomarker in oral cancer.

ImmunoPET imaging of tissue factor expression in pancreatic cancer with 89Zr-Df-ALT-836

Overexpression of tissue factor (TF) has been associated with increased tumor growth, tumor angiogenesis, and metastatic potential in many malignancies, including pancreatic cancer. Additionally, high TF expression was shown to strongly correlate with poor prognoses and decreased survival in pancreatic cancer patients. Herein, we exploited the potential targeting of TF for positron emission tomography (PET) imaging of pancreatic cancer. The TF-targeted tracer was developed through radiolabeling of the anti-human TF monoclonal antibody (ALT-836) with ⁸⁹Zr. The tracer was characterized by fluorescence microscopy and flow cytometry assays in BXPC-3 and PANC-1 cells, two pancreatic cancer cell lines with high and low TF expression levels, respectively. Non-invasive PET scans were acquired in tumor-bearing mice injected with ⁸⁹Zr-Df-ALT-836. Additionally, ex vivo biodistribution, blocking, and histological studies were performed to establish the affinity and specificity of ⁸⁹Zr-Df-ALT-836 for TF in vivo. ⁸⁹Zr-labeling of Df-ALT-836 was achieved in high yield and good specific activity. Flow cytometry and microscopy studies revealed no detectable difference in TF-binding affinity between ALT-836 and Df-ALT-836 in vitro. Longitudinal PET scans unveiled a lasting and prominent ⁸⁹Zr-Df-ALT-836 uptake in BXPC-3 tumors (peak at 31.5±6.0%ID/g at 48h post-injection; n=3), which was significantly abrogated (2.3±0.5%ID/g at 48h post-injection; n=3) when mice were pre-injected with a blocking dose (50mg/kg) of unlabeled ALT-836. Ex vivo biodistribution data confirmed the accuracy of the PET results, and histological analysis correlated high tumor uptake with in situ TF expression. Taken together, these results attest to the excellent affinity and TF-specificity of ⁸⁹Zr-Df-ALT-836. With elevated, persistent, and specific accumulation in TF-positive BXPC-3 tumors, PET imaging using ⁸⁹Zr-Df-ALT-836 promises to open new avenues for improving future diagnosis, stratification, and treatment response assessment in pancreatic cancer patients.

Coagulation and fibrinolysis in gastric cancer

Coagulation is a highly conserved process occurring after an injury to a blood vessel and resulting in hemostasis. In the thrombus microenvironment, finely orchestrated events restore vessel integrity through platelet activation, adhesion, and aggregation (primary hemostasis), followed by the coagulation cascades, thrombin generation, and fibrin clot deposition (secondary hemostasis). Several studies on cancer have provided insight into dramatic changes to coagulation-related events (i.e., fibrin clot deposition, fibrinolysis) during tumor pathogenesis, progression, and metastasis, in addition to a tumor-driven systemic activation of hemostasis and thrombosis (Trousseau's syndrome). Diverse molecular and cellular effectors participate in the cross talk between hemostasis and tumors. Here, we focus on some aspects of the interconnection between cancer biology and hemostatic components, with particular attention to some key coagulation-related proteins (e.g., tissue factor, thrombin, fibrinogen, and D-dimers) in the particular case of gastric cancer (GC). Recent advances in deciphering the complex molecular link between GC and the coagulation system are described, showing their important roles in better management of patients affected by GC.

A tissue factor-cascade-targeted nanoparticle forsite-directed inducing thrombosis

Tissue factor is an upstream component of the cascade and a high-expressing factor under phathological conditions. In this study, a tissue factor cascade-targeted strategy for inducing local thrombosis was developed by combining ENP-HMME and photochemistry. In vitro study showed that protein EGFP-EGF1 conjugation to the nanoparticles could significantly contribute to the uptake of nanoparticles by tissue factor over-expressed brain capillary endothelial cells. Three-dimensional imaging and specklegram of brains in vivo showed that tissue factor cascade-targeted strategy successfully induced thrombosis of expected position. As shown by the in vivo multispectral fluorescent imaging, when ENP-HMME was combined with photochemistry, higher accumulation in the infarction hemisphere was observed, which might suggest that the photochemistry inducing tissue factor cascade recruited more ENP-HMME than HMME-loaded nanoparticles (NP-HMME). The data indicated the tissue factor cascade-targeted strategy has potential to induce local thrombosis, and might be applied in the treatment of a variety of hypervascular diseases.

Patterns and functional implications of platelets upon tumor "education"

While platelets are traditionally recognized to play a predominant role in hemostasis and thrombosis, increasing evidence verifies its involvement in malignancies. As a component of the tumor microenvironment, platelets influence carcinogenesis, tumor metastasis and chemotherapy efficiency. Platelets status is thus predictable as a hematological biomarker of cancer prognosis and a hot target for therapeutic intervention. On the other hand, the role of circulating tumor cells (CTCs) as an inducer of platelet activation and aggregation has been well acknowledged. The cross-talk between platelets and CTCs is reciprocal on that the CTCs activate platelets while platelets contribute to CTCs' survival and dissemination. This review covers some of the current issues related to the loop between platelets and tumor aggression, including the manners of tumor cells in "educating" platelets and biofunctional alterations of platelets upon tumor "education". We also highlight the potential clinical applications on the interplay between tumors and platelets. Further studies with well-designed prospective multicenter trials may contribute to clinical "liquid biopsy" diagnosis by evaluating the global changes of platelets.

Targeting Platelets for the Treatment of Cancer

The majority of cancer-associated mortality results from the ability of tumour cells to metastasise leading to multifunctional organ failure and death. Disseminated tumour cells in the blood circulation are faced with major challenges such as rheological shear stresses and cell-mediated cytotoxicity mediated by natural killer cells. Nevertheless, circulating tumour cells with metastatic ability appear equipped to exploit host cells to aid their survival. Despite the long interest in targeting tumour-associated host cells such as platelets for cancer treatment, the clinical benefit of this strategy is still under question. In this review, we provide a summary of the latest mechanistic and clinical evidence to evaluate the validity of targeting platelets in cancer.

Coagulation factor VIIa-mediated protease-activated receptor 2 activation leads to β-catenin accumulation via the AKT/GSK3β pathway and contributes to breast cancer progression

Cell migration and invasion are very characteristic features of cancer cells that promote metastasis, which is one of the most common causes of mortality among cancer patients. Emerging evidence has shown that coagulation factors can directly mediate cancer-associated complications either by enhancing thrombus formation or by initiating various signaling events leading to metastatic cancer progression. It is well established that, apart from its distinct role in blood coagulation, coagulation factor FVIIa enhances aggressive behaviors of breast cancer cells, but the underlying signaling mechanisms still remain elusive. To this end, we investigated FVIIa's role in the migration and invasiveness of the breast cancer cell line MDA-MB-231. Consistent with previous observations, we observed that FVIIa increased the migratory and invasive potential of these cells. We also provide molecular evidence that protease-activated receptor 2 activation followed by PI3K-AKT activation and GSK3β inactivation is involved in these processes and that β-catenin, a well known tumor-regulatory protein, contributes to this signaling pathway. The pivotal role of β-catenin was further indicated by the up-regulation of its downstream targets cyclin D1, c-Myc, COX-2, MMP-7, MMP-14, and Claudin-1. β-Catenin knockdown almost completely attenuated the FVIIa-induced enhancement of breast cancer migration and invasion. These findings provide a new perspective to counteract the invasive behavior of breast cancer, indicating that blocking PI3K-AKT pathway-dependent β-catenin accumulation may represent a potential therapeutic approach to control breast cancer.

Prognostic values of tissue factor and its alternatively splice transcripts in human gastric cancer tissues

We have previously reported that the higher expression of TF in human esophageal cancer tissues was significantly associated with tumor invasion, intratumoral microvessel density and patients' postoperative prognoses. Besides its trans-membranous form, TF also has alternatively spliced transcripts. In the present study, the transcripts of the two TF isoforms, flTF and asTF, in human gastric cancer tissues were determined by real-time PCR, and the correlation between the expression of TF isoforms and patient's clinicopathological features was also analyzed. Our results showed that the relative mRNA expression levels of flTF and asTF in human gastric cancer tissues was significantly higher than those in normal tissues (P=0.035 and P=0.006, respectively). The relative mRNA expression level of asTF was significantly associated with age (P=0.018), meanwhile, we could not find that flTF or asTF expression level was correlated with any other characteristics of the patients, including gender, TNM stage, pathological grade, tumor size, histological type, or chemotherapy sensitivity. Univariate analysis demonstrated that the overall survival rate of gastric cancer patients with lower flTF or asTF expression level was greater than those with higher expression level (P=0.018 and =0.038, respectively). Multivariate COX model analysis also demonstrated that flTF expression (P=0.048) or asTF expression (P=0.002) could be used as independent prognostic predictors in human gastric cancer. Thus, both flTF and asTF mRNA expression levels in cancer tissues could be used as useful risk factors for evaluating the prognoses of patients suffering from gastric cancer.

Role of monocyte tissue factor on patients with non-small cell lung cancer

BACKGROUND

To examine the expression of D-dimer, fibrinogen (FIB), leukocyte, C-reactive protein (CRP) and tissue factor (TF) released from monocyte in non-small cell lung cancer (NSCLC) patients with or without venous thromboembolism (VTE) and analyse the correlation, to explore the possible mechanisms.

METHODS

Seventy-two patients confirmed the diagnosis of lung cancer, among whom 10 with VTE were enrolled into the study from November 2012 to January 2014 in the First Affiliated Hospital of Fujian Medical University and 30 healthy subjects were also enrolled as the control group. Ficoll and Percoll density gradient centrifugation separated of peripheral blood monocyte. Monocyte TF mRNA expression was detected using reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

There were significant differences in different stages of the cancer (P < .05) and no significance among the histopathologic types (P > .05) for the expression of monocyte TF mRNA in NSCLC patients, its expression was significantly higher in cancer with lymph node metastasis than those without lymph node metastasis (P < .01). Meanwhile, in NSCLC patients with VTE, the expression of monocyte TF mRNA was significantly higher than that in patients without VTE (P < .01). Difference of the survival curves between the low monocyte TF mRNA expression and the high monocyte TF mRNA expression was significant (Log-rank x2 = 4.923, P < .05).

CONCLUSIONS

Monocyte TF may be a relevant source of TF-mediated thrombogenicity in NSCLC patients and may be associated with prognosis in NSCLC.

Potential Coagulation Factor-Driven Pro-Inflammatory Responses in Ovarian Cancer Tissues Associated with Insufficient O₂ and Plasma Supply

Tissue factor (TF) is a cell surface receptor for coagulation factor VII (fVII). The TF-activated fVII (fVIIa) complex is an essential initiator of the extrinsic blood coagulation process. Interactions between cancer cells and immune cells via coagulation factors and adhesion molecules can promote progression of cancer, including epithelial ovarian cancer (EOC). This process is not necessarily advantageous, as tumor tissues generally undergo hypoxia due to aberrant vasculature, followed by reduced access to plasma components such as coagulation factors. However, hypoxia can activate TF expression. Expression of fVII, intercellular adhesion molecule-1 (ICAM-1), and multiple pro-inflammatory cytokines can be synergistically induced in EOC cells in response to hypoxia along with serum deprivation. Thus, pro-inflammatory responses associated with the TF-fVIIa-ICAM-1 interaction are expected within hypoxic tissues. Tumor tissue consists of multiple components such as stromal cells, interstitial fluid, albumin, and other micro-factors such as proton and metal ions. These factors, together with metabolism reprogramming in response to hypoxia and followed by functional modification of TF, may contribute to coagulation factor-driven inflammatory responses in EOC tissues. The aim of this review was to describe potential coagulation factor-driven inflammatory responses in hypoxic EOC tissues. Arguments were extended to clinical issues targeting this characteristic tumor environment.

Increased thrombin generation in a mouse model of cancer cachexia is partially interleukin-6 dependent

Essentials Cancer cachexia and cancer-associated thrombosis have not previously been mechanistically linked. We assessed thrombin generation and coagulation parameters in cachectic C26 tumor-bearing mice. C26 mice are hypercoagulable, partially corrected by blocking tumor derived interleukin-6. Coagulability and anti-inflammatory interventions may be clinically important in cancer cachexia.

SUMMARY

Background Cancer cachexia and cancer-associated thrombosis are potentially fatal outcomes of advanced cancer, which have not previously been mechanistically linked. The colon 26 (C26) carcinoma is a well-established mouse model of complications of advanced cancer cachexia, partially dependent on high levels of interleukin-6 (IL-6) produced by the tumor. Objectives To assess if cancer cachexia altered the coagulation state and if this was attributable to tumor IL-6 production. Methods In male BALB/c*DBA2 (F1 hybrid) mice with a C26 tumor we used modified calibrated automated thrombogram and fibrin generation (based on overall hemostatic potential) assays to assess the functional coagulation state, and also examined fibrinogen, erythrocyte sedimentation rate (ESR), platelet count, tissue factor pathway inhibitor (TFPI) and hepatic expression of coagulation factors by microarray. C26 mice were compared with non-cachectic NC26, pair-fed and sham control mice. IL-6 expression in C26 cells was knocked down by lentiviral shRNA constructs. Results C26 mice with significant weight loss and highly elevated IL-6 had elevated thrombin generation, fibrinogen, ESR, platelets and TFPI compared with all control groups. Fibrin generation was elevated compared with pair-fed and sham controls but not compared with NC26 tumor mice. Hepatic expression of coagulation factors and fibrinolytic inhibitors was increased. Silencing IL-6 in the tumor significantly, but incompletely, attenuated the increased thrombin generation, fibrinogen and TFPI. Conclusions Cachectic C26 tumor-bearing mice are in a hypercoagulable state, which is partly attributable to IL-6 release by the tumor. The findings support the importance of the coagulation state in cancer cachexia and the clinical utility of anti-inflammatory interventions.

Undercover Agents: Targeting Tumours with Modified Platelets

Platelets have long been recognised to colocalise with tumour cells throughout haematogenous metastasis. Interactions between these cells contribute to tumour cell survival and motility through the vasculature into other tissues. Now, the research focus is shifting towards developing means to exploit this relationship to provide accurate diagnostics and therapies. Alterations to platelet count, RNA profile, and platelet ultrastructure are associated with the presence of certain malignancies, and may be used for cancer detection. Additionally, nanoparticle-based drug delivery systems are enhanced through the use of platelet membranes to specifically target cancer cells and camouflage the foreign particles from the immune system. This review discusses the development of platelets into highly powerful tools for cancer diagnostics and therapies.

Pancreatic Cancer-Induced Neutrophil Extracellular Traps: A Potential Contributor to Cancer-Associated Thrombosis

Pancreatic cancer (PaCa) is a highly metastatic cancer, and patients are at high risk of developing venous thromboembolism (VTE). Neutrophil extracellular traps (NETs) have been associated with cancer metastasis and cancer-associated thrombosis, but the ability of cancer to stimulate NET release is not known. The release of NETs has been shown to be a slow process and requires reactive oxygen species (ROS) production. Studies suggest that activated platelets are important mediators in the release. Here, we show that PaCa cells can stimulate the rapid release of NETs, independently of ROS production. We further assessed the role of platelets in PaCa-induced NETs and observed a trend of increased the NET release by PaCa-primed platelets. Additionally, NETs promoted thrombus formation under venous shear stress ex vivo. Taken together, our results suggest that PaCa-induced NETs can contribute to the high risk of venous thromboembolism development in PaCa patients, and reveal NETs as a potential therapeutic target.

Thrombin-unique coagulation system protein with multifaceted impacts on cancer and metastasis

The association between blood coagulation and cancer development is well recognized. Thrombin, the pleiotropic enzyme best known for its contribution to fibrin formation and platelet aggregation during vascular hemostasis, may also trigger cellular events through protease-activated receptors, PAR-1 and PAR-4, leading to cancer progression. Our pioneering findings provided evidence that thrombin contributes to cancer metastasis by increasing adhesive potential of malignant cells. However, there is evidence that thrombin regulates every step of cancer dissemination: (1) cancer cell invasion, detachment from primary tumor, migration; (2) entering the blood vessel; (3) surviving in vasculature; (4) extravasation; (5) implantation in host organs. Recent studies have provided new molecular data about thrombin generation in cancer patients and the mechanisms by which thrombin contributes to transendothelial migration, platelet/tumor cell interactions, angiogenesis, and other processes. Though a great deal is known regarding the role of thrombin in cancer dissemination, there are new data for multiple thrombin-mediated events that justify devoting focus to this topic with a comprehensive approach.

D-dimer is an essential accompaniment of circulating tumor cells in gastric cancer

BACKGROUND

Fibrinogen (FIB) is an important source of fibrin, which plays a crucial role in circulating tumor cells (CTCs) extravasation and distant metastasis development. We hypothesize it's stable final product, plasma D-dimer, may be associated with CTCs appearance and can reflect the metastatic phenotype in cancer patients.

METHODS

We first verified our hypothesis in different murine gastric cancer metastasis models in vivo, plasma D-dimer and fibrinogen as well as its degradation products were directly examined in three metastasis immune-deficient mouse models and in controls. Next, we gathered and analyzed the result of plasma D-dimer levels and CTCs numbers in 41 advanced primary gastric cancer (GC) patients. A follow-up study was conducted in these patients.

RESULTS

In three in vivo murine metastasis models, plasma D-dimer levels were extremely elevated in a hematogenous and intraperitoneal murine model of metastasis compared with a subcutaneous tumor model and the control group, supporting our previous hypothesis. While in 41 GC patients, the result displayed that plasma D-dimer levels were remarkably increased in patients with distant metastases, especially in visceral metastases patients. Additionally, linear association was shown between D-dimer level and CTCs numbers (R ² = 0.688, p < 0.001), additionally, plasma D-dimer represent a better survival predictor than CTCs.

CONCLUSIONS

Plasma D-dimer is an essential accompaniment of CTCs in GC that is easy to measure and lower in cost, and can be used in the detection of hematogenous metastasis.

Cancer and Thrombosis: The Platelet Perspective

Platelets are critical to hemostatic and immunological function, and are key players in cancer progression, metastasis, and cancer-related thrombosis. Platelets interact with immune cells to stimulate anti-tumor responses and can be activated by immune cells and tumor cells. Platelet activation can lead to complex interactions between platelets and tumor cells. Platelets facilitate cancer progression and metastasis by: (1) forming aggregates with tumor cells; (2) inducing tumor growth, epithelial-mesenchymal transition, and invasion; (3) shielding circulating tumor cells from immune surveillance and killing; (4) facilitating tethering and arrest of circulating tumor cells; and (5) promoting angiogenesis and tumor cell establishment at distant sites. Tumor cell-activated platelets also predispose cancer patients to thrombotic events. Tumor cells and tumor-derived microparticles lead to thrombosis by secreting procoagulant factors, resulting in platelet activation and clotting. Platelets play a critical role in cancer progression and thrombosis, and markers of platelet-tumor cell interaction are candidates as biomarkers for cancer progression and thrombosis risk.